Also, as I stated earlier, high ppm and high pH tap/well water tend to be high in bicarbonates. Calcium carbonate isn't a readily available source of calcium to begin with, and bicarbonates will make most calcium carbonate inaccessible to the plant. Calcium carbonate is best used as a soil amendment and let breakdown for awhile as it's the primary driver of soil chemistry and is responsible for oxygen levels in the soil. Calcium is also the main nutrient that 99% of soils don't have enough of(even in all the fancy amended soils people use). Oxygen happens to be the most important element in the soil--especially for the roots and the microbes. Readily available forms of calcium are gypsum, amino acid chelated calcium, and calcium carbonate (oyster shell, calcitic lime, bone meal) that has been "cooked" in ewc or compost. For the plant to integrate calcium into it's structure, there must be sufficient boron as well.
Edit- I agree that knowing the pH of your water/nutrient solutions is important in organics. It's also important to know the exact chemical composition of the soil via a soil analysis. However, both are useless if a person doesn't know what they mean.